We used statewide surveillance data to describe the epidemiology of invasive Haemophilus influenzae type a (Hia) disease in Alaska during 2018-2022. Of 52 cases identified, 39 (75%) occurred among Alaska Native children aged <5 years who lived in rural areas of southwest or northern Alaska. Average annual incidence was 17.8 per 100,000 among children aged <5 years compared to 0.3 per 100,000 among persons aged ≥5 years. Among 43 cases in children aged <5 years, 16 (37%) presented with meningitis and 6 (14%) died. Characterizing Hia disease epidemiology can help direct prevention strategies, including vaccine development and use.

We describe the epidemiology of invasive group B streptococcal (GBS) disease among non-pregnant Alaska adults using statewide surveillance data. During 2004-2023, 880 cases of invasive GBS disease were reported for an age-adjusted annual incidence of 9.1 (95% CI, 8.5-9.7) cases per 100,000 adults. Incidence increased 1.9-fold (95% CI, 1.6-2.2) between 2004-2013 and 2014-2023. Adults aged ≥65 years had a 4.4-fold higher risk of invasive disease compared to younger adults, and 47% of adults with invasive GBS had diabetes. Healthcare providers should be aware of populations at increased risk, potentially allowing for more prompt treatment.

BACKGROUND: Adults aged ≥65 years, adults with certain underlying medical conditions, and persons experiencing homelessness are at increased risk for invasive pneumococcal disease (IPD). Two new pneumococcal conjugate vaccines, 15-valent pneumococcal conjugate vaccine (PCV15) and 20-valent pneumococcal conjugate vaccine (PCV20), were recently approved for use in U.S. adults. We described the epidemiology of IPD among Alaska adults and estimated the proportion of IPD cases potentially preventable by new vaccines. METHODS: We used statewide, laboratory-based surveillance data to calculate and compare IPD incidence rates and 95% confidence intervals (CI) among Alaska adults aged ≥18 years during 2011-2020 and estimate the proportion of IPD cases that were caused by serotypes in PCV15 and PCV20. RESULTS: During 2011-2020, 1,164 IPD cases were reported among Alaska adults for an average annual incidence of 21.3 cases per 100,000 adults per year (95% CI: 20.1-22.5). Incidence increased significantly during the study period (p<0.01). IPD incidence among Alaska Native adults was 4.7 times higher than among non-Alaska Native adults (95% CI: 4.2-5.2). Among adults experiencing homelessness in Anchorage, IPD incidence was 72 times higher than the general adult population (95% CI: 59-89). Overall, 1,032 (89%) Alaska adults with IPD had an indication for pneumococcal vaccine according to updated vaccination guidelines; 456 (39%) and 700 (60%) cases were caused by serotypes in PCV15 and PCV20, respectively. CONCLUSIONS: Use of PCV15 and PCV20 could substantially reduce IPD among adults in Alaska, including Alaska Native adults and adults experiencing homelessness.

Streptococcus pneumoniae can co-infect persons who have viral respiratory tract infections. However, research on S. pneumoniae infections that are temporally associated with SARS-CoV-2 infections is limited. We described the epidemiology and clinical course of patients who had invasive pneumococcal disease (IPD) and temporally associated SARS-CoV-2 infections in Alaska, USA, during January 1, 2020-December 23, 2021. Of 271 patients who had laboratory-confirmed IPD, 55 (20%) had a positive SARS-CoV-2 test result. We observed no major differences in age, race, sex, or underlying medical conditions among IPD patients with and without SARS-CoV-2. However, a larger proportion of IPD patients with SARS-CoV-2 died (16%, n = 9) than for those with IPD alone (4%, n = 9) (p<0.01). IPD patients with SARS-CoV-2 were also more likely to be experiencing homelessness (adjusted OR 3.5; 95% CI 1.7-7.5). Our study highlights the risk for dual infection and ongoing benefits of pneumococcal and COVID-19 vaccination, especially among vulnerable populations.